Twitter reports a loss but growing number of users

Investors have been worried about slowing user growth at the micro-blogging service

Social networking service Twitter reported a loss of $145m (£86m) during the second-quarter period from March to June.

That is more than triple the loss the company reported during the same period a year ago.

Twitter said it had 271 million monthly users - up 24% from a year ago - allaying investor fears that the service is not growing fast enough.

Shares in the firm soared over 35% in after-hours trading.

"Our strong financial and operating results for the second quarter show the continued momentum of our business," said chief executive Dick Costolo in a statement, noting Twitter's strong user figures during the World Cup.

However, in an interview with CNBC, Mr Costolo said that it was not just the World Cup that drove user growth, in an effort to allay fears that the company would not be able to keep the users it gained during the sporting event.

Twitter said it added 16 million new users during the March to June period - 13 million internationally and 3 million in the US.

Advertising revenue grew 129% from the same period a year earlier to $277m. Crucially for investors worried about shifting user habits, a majority of that advertising revenue came from mobile advertising.

Twitter said more than 78% of its clients access the service on their mobile devices.